FIGURE 3.
Comparison of GFP expression in the WT strain overexpressing WT MazF from the PBAD promoter and when expressing MazF from its own promoter after activation by E24A MazF. GFP expression was monitored as a function of time by flow cytometry. WT strain transformed with pBAD24 containing either the wild type mazF gene or the E24AmazF gene was induced at an A600 of 0.2 with 0.2% arabinose. The red and blue histograms correspond to GFP expression in cells overexpressing WT MazF and E24A MazF, respectively. The filled curve represents the GFP uninduced control. Although overexpression of WT MazF from the PBAD promoter completely abolishes GFP expression, expression of lower levels of free MazF from its cognate promoter only partially inhibited GFP expression.